feat: wire watch

Author: cmilesio

README.md

@@ -142,6 +142,26 @@ wire
 Wire produces `wire_gen.go` containing explicit initialization code with no
 runtime dependency on Wire.
 
+## Running generation manually
+
+Run the default command (alias for `wire gen`) or specify packages:
+
+```sh
+wire
+wire gen ./...
+```
+
+## Watching for changes
+
+Wire includes a native watcher that re-runs generation on Go file changes:
+
+```sh
+wire watch
+wire watch ./...
+```
+
+Detects the package root automatically and uses native filesystem notifications when available (with a polling fallback).
+
 ## Design Guidance
 
 Wire favors explicitness and long-term maintainability:
@@ -188,4 +208,3 @@ For questions and discussion, use
 
 This project follows the Go
 [Code of Conduct](./CODE_OF_CONDUCT.md).
-

cmd/wire/gen_cmd.go

@@ -108,7 +108,7 @@ func (cmd *genCmd) Execute(ctx context.Context, f *flag.FlagSet, args ...interfa
 			continue
 		}
 		if err := out.Commit(); err == nil {
-			log.Printf("%s: wrote %s\n", out.PkgPath, out.OutputPath)
+			log.Printf("%s: wrote %s (%s)\n", out.PkgPath, out.OutputPath, formatDuration(time.Since(totalStart)))
 		} else {
 			log.Printf("%s: failed to write %s: %v\n", out.PkgPath, out.OutputPath, err)
 			success = false

cmd/wire/main.go

@@ -43,6 +43,7 @@ func main() {
 	subcommands.Register(&cacheCmd{}, "")
 	subcommands.Register(&diffCmd{}, "")
 	subcommands.Register(&genCmd{}, "")
+	subcommands.Register(&watchCmd{}, "")
 	subcommands.Register(&showCmd{}, "")
 	flag.Parse()
 
@@ -65,6 +66,7 @@ func main() {
 		"gen":      true,
 		"serve":    true,
 		"show":     true,
+		"watch":    true,
 	}
 	// Default to running the "gen" command.
 	if args := flag.Args(); len(args) == 0 || !allCmds[args[0]] {